Investigation of Coherent Dissociation 10 C Nuclei at an Energy of 1.2 A GeV

1. Investigation of Coherent Dissociation 10C Nuclei at an Energy of 1.2 A GeV MamatkulovKahramon LHEP, JINR, Dubna JSPI, Uzbekistan EMIN’15 05-08 October 2015

2. Energy levels of 10C Example of microphotograph

3. Irradiation of the emulsion in the beam nuclei Be, C and N with energy 1.2 A GeV Amplitude spectrum from a scintillation counter, shows the positions of the peaks for nuclei with charges Zpr = 4, 6 and 7

4. Analysis of the primary beam • Viewed plates – 12 pcs. • The total length of viewing of primary tracks– 1088.1 m. • Number of total events – 7241 • Number of events ("white stars“) – 608 Distribution of tracks beam nuclei by the number of δ-electrons Nδ per 1 mm of the tracks length.

5. The charge topology of "white" stars Distribution by channels of dissociation of "white" stars Nws and events with fragments of the target or born mesons Ntr

6. Identification of the relativistic isotopes H and He Distribution of the fragments by value pβc of the "white" stars 10C  2He + 2H. 3He fragments from events of fragmentation 9С 33Не at 1.2 A GeV.

7. Angle distributions of fragments Rayleigh distribution for p and α (p) = (51 ± 3) × 10-3rad (α) = (17 ± 1) × 10-3rad by the statistical model (p) ≈ 47× 10-3 rad (α) ≈ 19 × 10-3 rad Distribution of the fragments of the polar of emission angle formed in the "white stars" 10C → 2α + 2p. (dotted line - p, solid line - α fragments)

8. Distribution of “white” stars 10С → 2α + 2p (solid line) and9Be → 2α + n (dotted line) by the value Θ2α. Inset - the distribution of events in the area Θn. Distribution parameters of “white” star 10C→2α + 2p and 9Be → 2α + n events by value opening angle of α-particle Θ2α.

9. Decays of unstable nuclei and rare events Formation of nuclei9B < Q2α > = (63 ± 30) keV, RMS= 83 keV <Q2αp> = (254 ± 18) keV,RMS = 96 keV The distribution of "white" stars 10C→2α+2p by excitation energy Q2α pairs α-particles; inset - increased distribution Q2α (a); distribution of events Q2αp triples 2a + p; inset - increased distribution Q2αp (b).

10. 10С → 9В+р → 8Ве+2р → 2α+2р(30%) Rayleigh distribution Pt(9В) = (92  15)МeV/c by the statistical model Pt(9В) =93 MeV/c Distribution of the total transverse momentum PT2αptriple 2α+p from decays of 9B nuclei in "white" stars 10C → 2α + 2p; curve – statistical model.

11. Cases of scattering nuclei9B <θ9B> = 9.2 ± 0.8 mrad, RMS =6.2 ± 0.6 mrad Condition θ9B<13 mrad: <θ9B> = 6.7 ± 0.4 mrad, RMS = 3.1 ± 0.3 mrad Distribution by the angle of emission of the nuclei9B in «white» stars10С → 2α + 2р.

12. The three-dimensional picture of the direction of emission of the nucleus 9B (2α + p) at large angles in the "white" stars 10C→ 9B + p (event № 602-04-11).

13. Reflection of the nuclear resonances Distribution on the opening angle between α-particles Θ2αandpairs αpΘαpin «white» stars10С → 2α + 2p.

14. Distribution of energy pairs α-particleQ2αandtriple α2pQα2pin «white» stars10С→2α + 2p. Interpretation of share of statistics related to resonances 5Li and 6Be, is indicative and may serve as upper evaluation for future research.

15. Dissociation of deep bound states Distribution by channels of dissociation of «white» stars Nws.

16. Conclusions • Performed search of nuclear stars in the length of about 1088 meters in the layers of nuclear emulsions irradiated in a mixed beam, configured on the separation of relativistic nuclei 12N, 10C and 7Be. Identification of the charges of the beam nuclei and the fragments allowed to select 227 events dissociation of carbon, not accompanied by the formation of fragments of the target andmesons. • Established that a channel with two helium nuclei, and two hydrogen (2He + 2H) is 82%.Leading these channel corresponds to representations of the structure exactly the isotope 10C, and confirms the correctness of the beam. Among isotopes of He and H, identified by multiple scattering are present only 4He and 1H, that also corresponds to the dominance of the isotope 10C in the beam. On this basis, 184 events in this channel pair interpreted as alpha particles and protons (10C → 2α + 2p). • Done measurements of the polar and azimuthal angles of fragments, and also independent measuring angles scattering fragments in 184 events of coherent dissociation 10C → 2α + 2p. Create an array of measurement uses for complex analysis of the angular correlations fragments.

17. Established that in the distribution of the invariant mass, 60 triples fragments 2α + p correspond to the cascade decay of the nucleus 9B through the nucleus 8Be. Thus, in the structure of the nucleus 10C with probability not less than 30 % manifested unstable nucleus 9B, and unstable nucleus 8Be manifests itself only as a component of 9B. This conclusion is confirmed by the distribution of the total transverse momentum of the nuclei 9B, which in the main part described by the Rayleigh distribution with parameter (92 +15) MeV/c, corresponding to statistical model. Were found 10 events scattering nucleus 9B out of the fragmentation cone. • Discovered a rare event dissociation, indicating the existence in the nucleus 10C is deeply related cluster states 7Be + 3He and 23He + 4He with a weight of 8%. With a probability 4% observed events fully coherent dissociation of 10C nuclei to six hydrogen nuclei.

18. Thank you for attention!